Prior to the advent of vehicular navigation systems, drivers depended upon turn signaling and braking indicators of vehicles in front of them to anticipate lane changes and deceleration. If a driver failed to signal in advance, or at all, his intention to change lanes or to exit a highway, the risk of collisions increased commensurately.
Currently, with the increasing use of built-in and ad hoc navigation systems being used by drivers, they typically have a several-mile or several-kilometer advanced directive to move right or left and/or to exit at an upcoming exit. On regular roads with intersections and traffic signals, navigation systems offer preparatory directives to move and/or to turn right or left at upcoming intersections. This gives the driver who is unfamiliar with a route, or not paying attention, an advanced warning of upcoming need to move and/or turn and the like. However, vehicles traveling behind a vehicle so navigated must still depend upon turn and brake signaling in order to maintain safe inter-vehicle speed and spacing.
New technologies for navigation and automated vehicle control typically involve wireless conveyance of data among vehicles and roadside base stations. Assuming this sharing of wireless data among proximate vehicles will include upcoming navigation directives data, it becomes possible for following vehicles to get advanced knowledge of forward vehicle navigation directives, and impending actions, such as moving over and/or exiting. On regular roads, such actions could include moving over and/or turning right or left at intersections or destinations. The additional preparation time significantly lowers the risk of unanticipated actions of forward vehicles adding a significant increase in driving safety.
In conjunction with a vehicle's own built-in system of sensors that give real-time indications of inter-vehicle spacing, relative speed, and the like, the additional advanced navigation directives would provide heightened driving safety.